It is interesting: at what moment do the apostles actually become apostles? At the moment when Jesus called them to follow Him, each in his own hour? On the day when He sends them out for ministry? After His resurrection and their meeting with Him, risen from the dead? On the day of Pentecost? It is probably impossible to give a single answer to this question. After all, an apostle is above all a witness, a witness of Christ and of the Kingdom. That means he becomes an apostle at the moment when he begins to bear witness. And what should be counted as the beginning? In essence, the apostles fully understood what the Kingdom was only after Pentecost, when they experienced its breath upon themselves. But they became witnesses much earlier. In a certain sense, their very readiness to follow Jesus immediately after He called them can already be considered a witness.
Of course, the moment when Jesus sends His twelve closest disciples out to preach really does become a turning point on their spiritual path. Before that, they bore witness by their very presence beside the Teacher, by the support they gave Him. Now they had to give independent witness, to walk their own path, certainly connected with the earthly path of their Teacher, but still their own. At the same time, of course, the question arises by itself: how could the apostles bear witness to the Kingdom, which they truly came to know much later, after the Resurrection and Pentecost?
Here, as we can see, one of the fundamental patterns of spiritual life shows itself, as spiritual life exists in our world that is being transformed but has not yet been transformed, and perhaps not only here. The point is that in spiritual life what might conditionally be called training and, just as conditionally, practice exist inseparably. Spiritual life and practice cannot be learned the way we learn one specialty or another in a secondary school or university, so that after finishing the course we then begin work. There is not even the practical internship familiar in such schools. One has to work, so to speak, directly on the job from the very beginning, learning without leaving it. Such learning can sometimes appear too difficult and even risky, but this appears to be the only possibility, at least in our fallen world. And Jesus teaches His disciples exactly this way: on the road to the Kingdom. So that when they arrive there, they will already know and be able to do everything they need. At least at first.
